Both primary and metastatic liver cancer is common in the US, and worldwide. The standard treatment for liver cancer is liver resection, where part of the liver containing the tumor is surgically removed. Surgery is however only possible in ~20% of the patients, and Radiofrequency (RF) ablation is an accepted treatment method for patients where surgery is not possible. During RF ablation, an electrode is introduced into the tumor, and the cancer is destroyed by heating via RF current. Current RF ablation procedures have several shortcomings resulting in often insufficient treatment: (1) an inability to adequately treat even moderate sized tumors (>3.0 cm) with a single ablation, (2) inadequate performance close to large vessels, and (3) inadequate intraoperative imaging. We propose a new tumor ablation device that consists of an array of electrodes surrounding the tumor and directing bipolar energy from outside, instead of heating the tumor inside-out, as with current ablation devices. The device with circumferential electrodes will generate a more uniform, higher temperature profile in the treated tumor and overcome the cooling effect of vessels within the liver. Furthermore, the device will allow rapid treatment of large tumors with a single application which is not possible with current devices. This will make treatment planning considerably less complex, reducing procedure time for large tumor treatment, and likely also lower tumor recurrence rate, increasing the survival. Ablation time will be significantly reduced from currently 12-45 min to below 5 min. In addition, complications such as skin burns due to heating of dispersive electrodes and tumor seeding along needle insertion tracts will be avoided. PUBLIC HEALTH RELEVANCE: The device proposed in this project will, if successful, allow more effective treatment of liver cancer patients not treatable by surgery, reducing treatment times and ultimately improving patient survival. [unreadable] [unreadable] [unreadable]